Image forming apparatus, control method of image forming apparatus, and program

ABSTRACT

An image forming apparatus includes: an accepting unit to accept user operations to transition the apparatus from a standby state to a power save state; a detecting unit to detect objects around the apparatus; and a power control unit to transition the apparatus from the power save state to the standby state according to detection of an object by the detecting unit, and to transition the image forming apparatus from the standby state to the power save state according to user operations accepted at the accepting unit. The power control unit prohibits the apparatus from transitioning from the power save state to the standby state according to the detection of the object, until a user, which performed operations accepted by the accepting unit to transition the apparatus from the standby state to the power save state, thereafter ceases to be detected by the detecting unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.14/307,989, filed Jun. 18, 2014, which claims priority from JapanesePatent Application No 2013-131104 filed Jun. 21, 2013, which is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

One disclosed aspect of the embodiments relates to power mode switchingof an image forming apparatus using human presence detection technology.

2. Description of the Related Art

Conventional image processing apparatuses have multiple power modes, andsupport a power save mode where power within the apparatus isdisconnected depending on the power mode. However, return from the powersave mode to a normal power mode may take time, reducing convenience.

Japanese Patent Laid-Open No. 2012-58645 discloses solving this problemby using a human presence sensor to return from the conventional powersave mode, so that in a case where determination is made that a personis approaching the apparatus, the apparatus returns from the power savemode.

There also is an image processing apparatus provided with a power savekey to be pressed by user operations, disclosed in Japanese PatentLaid-Open No. 2002-229395. Upon the power save key being pressed, theimage forming apparatus transitions to power save mode.

However, in the art of Japanese Patent Laid-Open No. 2012-58645 andJapanese Patent Laid-Open No. 2002-229395, there may be cases where thepower save key is pressed, instructing the image forming apparatus totransition to the power save mode, while the human presence sensor isdetecting human presence. In this case, the image forming apparatustransitions to the power save mode since the power save key has beenpressed, but the user in front of the image forming apparatus who haspressed the power save key is detected by the human presence sensor.Accordingly, there has been a problem in which the image formingapparatus returns to normal power mode even though the power save keyhas been pressed, so power conservation is not realized.

SUMMARY OF THE INVENTION

An image forming apparatus, having at least a standby state, and a powersave state which consumes less power than the standby state, the imageforming apparatus includes: an accepting unit configured to accept useroperations to transition the image forming apparatus from the standbystate to the power save state; a detecting unit configured to detectobjects around the image forming apparatus; and a power control unitconfigured to transition the image forming apparatus from the power savestate to the standby state in accordance with detection of an object bythe detecting unit, and to transition the image forming apparatus fromthe standby state to the power save state in accordance with useroperations accepted at the accepting unit. The power control unitprohibits the image forming apparatus from transitioning from the powersave state to the standby state in accordance with detection of anobject by the detecting unit, until a user, which has performedoperations accepted by the accepting unit to transition the imageforming apparatus from the standby state to the power save state,thereafter ceases to be detected by the detecting unit.

Further features of the disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are diagrams illustrating an example of theconfiguration of an image forming apparatus representing an electronicdevice according to a first embodiment.

FIGS. 2A and 2B are diagrams illustrating examples of detection rangesof a first human presence sensor and a second human presence sensor.

FIGS. 3A through 3C are diagrams illustrating examples of the hardwareconfiguration of the image forming apparatus according to the firstembodiment.

FIG. 4 is a diagram illustrating an example of a power supplyarrangement of the image forming apparatus according to the firstembodiment.

FIG. 5 is a diagram illustrating an example of the configuration of ahuman presence sensor return determination unit according to the firstembodiment.

FIG. 6 is a flowchart illustrating an example of power mode transitionoperations according to the first embodiment.

FIG. 7 is a diagram illustrating an example of a power supplyarrangement of the image forming apparatus according to a secondembodiment.

FIG. 8 is a diagram illustrating an example of the configuration of ahuman presence sensor return determination unit according to the secondembodiment.

FIG. 9 is a flowchart illustrating an example of power mode transitionoperations according to the second embodiment.

FIGS. 10A and 10B are diagrams illustrating examples of theconfiguration of an image forming apparatus according to a thirdembodiment.

FIG. 11 is a diagram illustrating an example of the detection range of ahuman presence sensor array.

FIGS. 12A through 12D are diagrams illustrating examples of response ofa human presence sensor array.

FIGS. 13A and 13B are diagrams illustrating examples of the hardwareconfiguration of the image forming apparatus according to the thirdembodiment.

FIG. 14 is a diagram illustrating an example of a power supplyarrangement of the image forming apparatus according to the thirdembodiment.

FIG. 15 is a diagram illustrating an example of the configuration of ahuman presence sensor array determination unit according to the thirdembodiment.

FIG. 16 is a flowchart illustrating an example of power mode transitionoperations according to the third embodiment.

DESCRIPTION OF THE EMBODIMENTS

Embodiments to carry out the present embodiment will be described withreference to the drawings. One disclosed feature of the embodiments maybe described as a process which is usually depicted as a flowchart, aflow diagram, a structure diagram, or a block diagram. Although aflowchart may describe the operations as a sequential process, many ofthe operations may be performed in parallel or concurrently. Inaddition, the order of the operations may be re-arranged. A process isterminated when its operations are completed. A process may correspondto a method, a program, a procedure, etc. One embodiment may bedescribed by a schematic drawing depicting a physical structure. It isunderstood that the schematic drawing illustrates the basic concept andmay not be scaled or depict the structure in exact proportions.

It has been found desirable to provide a mechanism by which unnecessaryreturn from the power save state, due to detection by the human presencesensor after the power save key has been pressed, can be prevented.

First Embodiment

FIGS. 1A and 1B are diagrams illustrating an example of theconfiguration of an image forming apparatus representing an electronicdevice according to a first embodiment. FIG. 1A corresponds to a frontview of the image forming apparatus, and FIG. 1B corresponds to a topview of the image forming apparatus.

Reference numeral 100 denotes the image forming apparatus representingthe electronic device. The image forming apparatus 100 includes anoperating unit 101, scanner 102, built-in finisher 103, feed cassette104, and so forth, and functions such as copy, print, facsimile, scan,and so forth.

The image forming apparatus 100 has a normal power mode, a second powersave mode which consumes less power (e.g., electrical power) than thenormal power mode, and a first power save mode which consumes less power(e.g., electrical power) than the second power save mode, and can beswitched to any of these modes. The power state of the image formingapparatus 100 in the normal power mode, first power save mode, andsecond power save mode, will be referred to as first power state, secondpower state, and third power state, respectively. The image formingapparatus 100 is an image forming apparatus which can operate byswitching between at least the first power state and second power state.

The image forming apparatus 100 includes a first human presence sensor230 which operates in a first power save mode, and a second humanpresence sensor 231 which operates in a second power save mode. Thefirst human presence sensor 230 and second human presence sensor 231 usesensors to detect objects, such as pyroelectric sensors or reflectionsensors.

The first human presence sensor 230 is a first detecting unit whichdetects people approaching the image forming apparatus 100 over a widerange, and is configured using a pyroelectric sensor for example, todetect objects such as human bodies. The second human presence sensor231 is a second detecting unit which detects people approaching theimage forming apparatus 100 in a narrower range than the first humanpresence sensor 230, and is configured using a reflection sensor forexample, to detect objects such as human bodies. FIGS. 2A and 2Billustrate examples of the detecting ranges of the first human presencesensor 230 and second human presence sensor 231.

FIGS. 2A and 2B are diagrams illustrating examples of the detectionranges of the first human presence sensor 230 and second human presencesensor 231. FIG. 2A corresponds to a front view of the image formingapparatus 100, and FIG. 2B corresponds to a top view of the imageforming apparatus 100. In FIGS. 2A and 2B, reference numeral 111indicates the detection range of the first human presence sensor 230,while reference numeral 112 indicates the detection range of the secondhuman presence sensor 231.

FIG. 3A is a block diagram illustrating an example of the hardwareconfiguration of the image forming apparatus 100 according to the firstembodiment.

An information processing device 226 is connected to a local areanetwork (LAN) 224 via a LAN interface 217, and also is connected to atelephone line 223 via a FAX 225.

A central processing unit (CPU) 204 executes software programs tocontrol the overall information processing device 226. Random accessmemory (RAM) 206 is used to temporarily store data at the time of theCPU 204 controlling the device. Read only memory (ROM) 205 storesprograms which the CPU executes such as a start-up program for thedevice, various types of settings, and so forth. Storage 207 is astorage device such as a hard disk drive (HDD), solid state drive (SSD),or the like, and is used to store various types of data.

An operating unit interface 209 controls an operating unit 213 undercontrol of the CPU 204. The operating unit 213 includes a liquid crystalpanel having a touch panel for performing operations, hard keysincluding a power save key 214, to accept instructions input from users.

A scanner interface 210 controls a scanner 215 under control of the CPU204. The scanner 215 reads images of original documents placed on adocument positioning plate or run through an auto document feeder (ADF),and generates images. A printer interface 211 controls a printer 216under control of the CPU 204. The printer 216 prints images based onimage data, onto paper.

A FAX interface 208 controls the FAX 225 under control of the CPU 204.The FAX 225 includes a modem 218, CPU 219, RAM 221, ROM 220, and anincoming detection unit 222. The image forming apparatus 100 controlsdata communication with external devices connected over the telephoneline 223. A modem 218 performs modulation for transmission/reception bythe FAX 225. The CPU 219 controls transmission/reception of the FAX 225in coordination with the information processing device 226 via the FAXinterface 208. The RAM 221 is used to temporarily store data at the timeof the CPU 219 controlling the device. The ROM 220 stores programs suchas a start-up program for the FAX 225, various types of setting values,and so forth. The functions of the CPU 219, RAM 221, and ROM 220, of theFAX 225, may be included within the information processing device 226.

A LAN controller 212 controls the LAN interface 217 under control of theCPU 204. The image forming apparatus 100 controls data communicationwith external devices connected to a network 224.

A power source control unit 203 has a power control function to controlpower supplied from a power source unit 202 to wherever necessary. Inthe normal power mode, power is supplied to all blocks, as illustratedin FIG. 3A. An arrangement may be made where power is supplied only tonecessary functions at this time, but this arrangement will not bedescribed here.

In the first power save mode, power is not supplied to a part of theblocks, as illustrated in FIG. 3B. The grayed out portions in FIG. 3Bindicate that power is not being supplied thereto. The power supplystate in the first power save mode will now be described.

First, power is supplied to the power source unit 202 from the powersource 201. The blocks to which power is supplied from the power sourceunit 202 are the RAM 206, the first human presence sensor 230, a humanpresence sensor return determining unit 281, the FAX interface 208, theincoming detection unit 222, the power save key 214, the operating unitinterface 209, the LAN controller 212, and the LAN interface 217. Notethat power does not have to be supplied to the entire RAM 206, and maybe supplied only as necessary. While description has been made that onlythe power save key 214 of the operating unit 213 receives power supplyhere, power may be supplied to the operating unit 213 in accordance withtransition conditions to another power supply state, such as a functionof recognizing a user touch.

Next, transition conditions from the first power save mode to normalpower mode will be described. In a case where the incoming detectionunit 222 detects an incoming fax, the incoming detection unit 222transmits a transition command to the power source control unit 203 viathe FAX interface 208, thereby transitioning the power mode to thenormal power mode. In a case where the LAN interface 217 receives aprint job requiring transitioning to the normal control mode via the LANcontroller 212, the LAN controller 212 transmits a transition command tothe power source control unit 203, thereby transitioning the power modeto the normal power mode.

In a case where detection is made that the user has pressed the powersave key 214, a transition command is transmitted to the power sourcecontrol unit 203 via the operating unit interface 209 therebytransitioning the power mode to the normal power mode. While descriptionhas been made that only the power save key 214 of the operating unit 213receives power supply here, a configuration may be made where a usertouch is recognized, and an interruption is transmitted to the powersource control unit 203. Description of detailed flows relating to theembodiments and transition to the second power save mode has beenomitted in the transition conditions to the normal power mode describedso far, but it is needless to say that if the power source control unit203 receives a transition command partway through a flow, transition tothe normal power mode is performed.

Next, transitioning conditions from the first power save mode to thesecond power save mode will be described. In a case where the firsthuman presence sensor 230 detects a person approaching, the first humanpresence sensor 230 transmits a transition command to the power sourcecontrol unit 203, to transition to the second power save mode, and thepower source control unit 203 transitions to the second power save mode.In the second power save mode, power is supplied to a part of theblocks, as illustrated in FIG. 3C. The grayed out portions in FIG. 3Cindicate that power is not being supplied thereto.

Next, the difference between the second power save mode and the firstpower save mode will be described. In the second power save mode, poweris supplied to the second human presence sensor 231. The second powersave mode is maintained as long as the first human presence sensor 230is detecting a person. When the first human presence sensor 230 can nolonger detect a person, the first human presence sensor 230 transmits atransition command to the power source control unit 203, to transitionto the first power save mode, and the power source control unit 203transitions to the first power save mode. In a case where the secondhuman presence sensor 231 detects a person approaching, the second humanpresence sensor 231 transmits a transmission command to the power sourcecontrol unit 203 via the human presence sensor return determining unit281, to transition to the normal power mode, and the power sourcecontrol unit 203 transitions to the normal power mode. The humanpresence sensor return determining unit 281 restricts signals from thesecond human presence sensor 231 to the power source control unit 203(the aforementioned transition command to the normal power mode) underpredetermined conditions, which will be described in detail later.

Next, power mode transition using human presence sensors will bedescribed in detail with reference to FIG. 4. FIG. 4 is a diagramillustrating an example of a power supply form of the image formingapparatus 100 according to the first embodiment.

Power source power input from the power source 201 is input to a switch310 and a switch 312. The switch 310 is configured as a seesaw switch,button switch, or the like, which the power source control unit 203 canturn on or the user can manually turn on. In a case where the switch 310is turned on, the power source control unit 203 may automaticallytransmit a turn-on command 512 to a switch 311, and a turn-on command513 to the switch 312, and transition to the normal power mode. A firstpower supply unit 300 receives supply of power by the switch 310 turningon, and supplies power to the blocks which operated under the firstpower save mode. While the FAX interface 208 and operating unitinterface 209 are omitted from illustration in FIG. 4, it is to beunderstood that the first power supply unit 300 supplies power theretoas well.

In a case where the switch 311 is turned on, power is supplied to asecond power supply unit 301 from the first power supply unit 300. Thesecond power supply unit 301 supplies power to the blocks operatingunder the second power save mode. Conditions of transitioning from thefirst power save mode to the second power save mode are detection of aperson by the first human presence sensor 230. The switch 311 and switch312 can be realized by field effect transistors (FET), relay switches,or the like.

Upon detecting a person, the first human presence sensor 230 transmits arequest signal 511 to the power source control unit 203, to turn on theswitch 311. Upon receiving the request signal 511, the power sourcecontrol unit 203 transmits a turn-on command 512 to the switch 311, andpower is supplied to the second power supply unit 301.

Next, transitioning conditions to normal power mode will be described.In a case where the power source control unit 203 receives even onerequest signal necessitating transitioning to normal power mode, thepower mode transitions to normal power mode. The following isdescription of each of request signals to transition to the normal powermode.

In a case of receiving a command necessitating transition to normalpower mode, such as a print job or the like, the LAN controller 212transmits a request command 501 to the power source control unit 203.Also, in a case of detecting an incoming fax, the incoming detection 222unit transmits a request command 502 to the power source control unit203. Note that in a case where the power save key 214 has been pressedby the user, the power save key 214 transmits a request command 503 tothe power source control unit 203. Also, in a case where the power savekey 214 has been pressed by the user, the power save key 214 outputs asignal 530 to the human presence sensor return determining unit 281 forinvalid flag processing.

Upon having received any of the above transition request signals, thepower source control unit 203 transmits a turn-on command 513 to theswitch 312, and power is supplied to a third power supply unit 302. Thethird power supply unit 302 supplies power to the blocks used in thenormal power mode. Though the scanner interface 210 and printerinterface 211 are omitted from illustration in FIG. 4, power is suppliedthereto from the third power supply unit 302 as well. The power suppliedfrom the power source 201 is split and delivered to the three of firstpower supply unit 300, second power supply unit 301, and third powersupply unit 302.

Next, description will be made regarding output of a transition requestsignal 504 based on the second human presence sensor 231. In a case ofhaving detected a person, the second human presence sensor 231 transmitsa detection signal 531 to the human presence sensor return determiningunit 281. The human presence sensor return determining unit 281determines whether the person which has instructed transitioning to thepower save mode by operating the power save key 214 has left the imageforming apparatus 100, and restricts returning from the power save modebased on the second human presence sensor 231.

In the present embodiment, in a case where a human presence sensor (thefirst human presence sensor 230, for example) continues to detect aperson after transitioning to the power save mode has been instructedfrom the power save key 214, the human presence sensor returndetermining unit 281 restricts output of the transition request signal504. In a case of transitioning to the power save mode due to other thanthe power save key 214, or in a case where a human presence sensorceases to detect a person after transitioning to the power save mode hasbeen instructed from the power save key 214, the human presence sensorreturn determining unit 281 cancels the output restriction on thetransition request signal 504. Whether or not a human presence sensor isdetecting a person has been described as being determined bytransmission from the power source control unit 203, but an arrangementmay be made where signals from the human presence sensor are transmittedto the human presence sensor return determining unit 281 fordetermination.

While the human presence sensor in the above description has beendescribed as being the first human presence sensor 230, determination atthe human presence sensor return determining unit 281 may be made anyway as long as being able to determine that the person who instructedtransitioning to the power save mode using the power save key 214, hasleft the vicinity of the image forming apparatus 100. Accordingly, thedetermination at the human presence sensor return determining unit 281may be made with the detection state of either or both of the firsthuman presence sensor 230 and second human presence sensor 231 as areference. Hereinafter, description will be made assuming that as longas the first human presence sensor 230 continues detection, the humanpresence sensor return determining unit 281 restricts the transitionrequest signal 504.

Output restriction of the transition request signal 504 by the humanpresence sensor return determining unit 281 will be described in detailnow with reference to FIG. 5. FIG. 5 is a diagram illustrating anexample of the configuration of the human presence sensor returndetermining unit 281 according to the first embodiment.

Upon the power save key 214 being pressed, a signal 530 is output fromthe power save key 214 to an invalid flag 600. The signal 530 is used toperform output restriction of the transition request signal 504 totransition to the normal power mode, based on the second human presencesensor 231. Also upon the power save key 214 being pressed, a power savemode transition instruction, omitted from illustration, is output fromthe power save key 214, and upon receiving this instruction the powersource control unit 203 transitions to the power save mode.

In a case of having transitioned to the power save mode under the powersave mode transition instruction from the power save key 214, the powersource control unit 203 continues to output a signal 532 to the invalidflag 600 to restrict the transition request signal 504, as long as thefirst human presence sensor 230 is detecting a person. The signal 532may be a detection signal of the first human presence sensor 230.

The invalid flag 600 sets a signal (hereinafter “human presence sensorinvalid flag”) 599 to “1” by default. Upon receiving the signal 530 fromthe power save key 214, the invalid flag 600 keeps the human presencesensor invalid flag 599 at “0” until reception of the signal 532 ceases.Further, upon reception of the signal 532 ceasing, the invalid flag 600returns the human presence sensor invalid flag 599 to “1”, and keeps thehuman presence sensor invalid flag 599 at “1” until the signal 530 isreceived again. In a case of receiving the signal 531 in a state wherethe human presence sensor invalid flag 599 is “1”, a logic 601 outputsthe transition request signal 504 to normal power mode based on thesecond human presence sensor 231 to the power source control unit 203.

FIG. 6 is a flowchart illustrating an example of a power mode transitionoperation in the image forming apparatus according to the firstembodiment.

Upon the power save key 214 of the image forming apparatus 100 beingpressed (Yes in S11), the signal 530 is output from the power save key214 to the invalid flag 600, and the invalid flag 600 sets the humanpresence sensor invalid flag 599 to “0” (S12). In a case where the humanpresence sensor invalid flag 599 is “0”, the transition request signal504 to normal power mode from the human presence sensor returndetermining unit 281 is restricted. Also when the power save key 214 ispressed, the power source control unit 203 performs transitionprocessing to the power save mode (S14). The power save mode to whichtransition is made here may be either the first power save mode or thesecond power save mode.

In a case where the power save key 214 has not been pressed (No in S11),but the power save mode transition conditions have been satisfied byother than pressing of the power save key 214 (Yes in S13), the powersource control unit 203 performs transition processing to the power savemode (S14). In this case, the human presence sensor invalid flag 599 isset to “1”. In a case where the human presence sensor invalid flag 599is set to “1”, the transition request signal 504 to the normal powermode from the human presence sensor return determining unit 281 is notrestricted. Note that power save mode transition conditions other thanthe power save key 214 include, for example, the image forming apparatus100 not being used for a predetermined amount of time.

After transitioning to the power save mode, the power source controlunit 203 determines whether or not the first human presence sensor 230is detecting (S40). In a case where determination is made that the firsthuman presence sensor 230 is detecting (Yes in S40), the flow advancesto S41; otherwise, the flow advances to S42.

In the event that the power mode at that time is the first power savemode, the power source control unit 203 transitions to the second powersave mode and supplies power to the second human presence sensor 231. Inthe event that the power mode at that time is the second power savemode, the power source control unit 203 maintains the power state.

In S42, in the event that the power mode at that time is the secondpower save mode, the power source control unit 203 transitions to thefirst power save mode and stops supply of power to the second humanpresence sensor 231. In the event that the power mode at that time isthe first power save mode, the power source control unit 203 maintainsthe power state.

In a case where the human presence sensor invalid flag 599 is “1” (No inS15), the human presence sensor return determining unit 281 can outputthe transition request signal 504 to the power source control unit 203in accordance with the detection signal 531 from the second humanpresence sensor 231.

In a case where the human presence sensor invalid flag 599 is “0” (Yesin S15), the invalid flag 600 effects control to change the humanpresence sensor invalid flag 599 in accordance with the signal 532 fromthe power source control unit 203 based on the detection state of ahuman presence sensor. Note that the human presence sensors in S15 maybe either the first human presence sensor 230 or the second humanpresence sensor 231, or both the first human presence sensor 230 andsecond human presence sensor 231 may be used for determination, sincethe purpose is to determine whether the user who has pressed the regionpower save key 214 has left the vicinity of the image forming apparatus100.

In a case where a human presence sensor is in a detecting state (No inS16), output of the signal 532 from the power source control unit 203 ismaintained, and accordingly the invalid flag 600 keeps the humanpresence sensor invalid flag 599 set to “0”. In a case where the humanpresence sensor invalid flag 599 is “0”, the human presence sensorreturn determining unit 281 does not transmit the transition requestsignal 504 to the power source control unit 203 even of the detectionsignal 531 is input from the second human presence sensor 231.

On the other hand, in a case where there is no detection by the humanpresence sensors (Yes in S16), output of the signal 532 from the powersource control unit 203 is stopped, and accordingly the invalid flag 600changes the human presence sensor invalid flag 599 to “1” (S17).

In a case where the human presence sensor invalid flag 599 is “1” (No inS15), the invalid flag 600 maintains the human presence sensor invalidflag 599 at “1” regardless of the signal 532 from the power sourcecontrol unit 203 based on the detection state of the human presencesensor (the first human presence sensor 230 in this case). In a casewhere the human presence sensor invalid flag 599 is “1”, and thedetection signal 531 is input from the second human presence sensor 231,the human presence sensor return determining unit 281 transmits atransition request signal 504 to the power source control unit 203.

In a case of receiving none of the request signals 511, 501, 502, 503,and 504, the power source control unit 203 determines that the normalpower mode transition conditions are not satisfied (No in S18), and theflow returns to S40 and determines whether or not the first humanpresence sensor 230 is detecting.

In a case of receiving any of the request signals 511, 501, 502, 503,and 504, the power source control unit 203 determines that the normalpower mode transition conditions are satisfied (Yes in S18), andtransitions to the normal power mode (S19).

Note that in a case where the human presence sensor invalid flag 599 is“0”, the transition request signal 504 to the normal power mode is notoutput from the human presence sensor return determining unit 281, soeven in a case where the second human presence sensor 231 senses aperson, the normal power mode transition conditions are not satisfied.On the other hand, that in a case where the human presence sensorinvalid flag 599 is “1”, the transition request signal 504 to the normalpower mode is not restricted, so in a case where the second humanpresence sensor 231 senses a person, the normal power mode transitionconditions are satisfied.

Thus, in a case where the power save key 214 is pressed and transitionto the power save mode is made, transition from the power save mode tothe normal power mode due to the human presence sensors operating can berestricted until the user which has pressed the power save key 214leaves the vicinity of the image forming apparatus 100. Accordingly,unnecessary return from the power save mode due to the human presencesensors detected after the power save key 214 is pressed can beprevented. As a result, reduction in unnecessary power consumption andextension of the life of parts of the apparatus can be realized whileimproving user usability.

Note that in the above description, a configuration has been illustratedwhere the human presence sensor return determining unit 281 restrictsoutput of the transition request signal 504, so as to restrict return tothe normal power mode due to detection by the second human presencesensor 231. However, a configuration may be made where no human presencesensor return determining unit 281 is provided, and the power sourcecontrol unit 203 directly controls return to the normal power mode dueto detection by the second human presence sensor 231. In this case, thedetection signal 531 of the second human presence sensor 231 is directlyinput to the power source control unit 203. In a case where the powersave key 214 is pressed and there also is detection by a human presencesensor (e.g., the first human presence sensor 230), the power sourcecontrol unit 203 ignores the input of the detection signal 531. Thiswill be described with reference to FIG. 6. In this case, the processesillustrated in FIG. 6 are realized by the power source control unit 203reading out and executing programs stored in a storage device within thepower source control unit 203.

In S11, the power source control unit 203 determines whether or not thepower save key 214 has been pressed. In a case where determination ismade that the power save key 214 has been pressed (Yes in S11), thepower source control unit 203 transitions to S12. In S12, the powersource control unit 203 sets the human presence sensor invalid flag 599to “0” and transitions to S14. This flag is stored in an unshown storageunit within the power source control unit 203, and is set to “1” bydefault.

On the other hand, in a case where determination is made in S11 that thepower save key 214 has not been pressed (NO in S11), the power sourcecontrol unit 203 transitions to S13. In S13, the power source controlunit 203 determines whether or not transition conditions to transitionto the power save mode have been satisfied. Note that determination oftransition conditions to the power save mode itself is performed by theCPU 204, and upon having received a transition instruction to the powersave mode from the CPU 204, the power source control unit 203 judgesthat transition conditions to transition to the power save mode havebeen satisfied.

In S13, in a case of having determined that transition conditions totransition to the power save mode have not been satisfied (No in S13),the power source control unit 203 transitions to S11. On the other hand,in a case of having determined that transition conditions to transitionto the power save mode have been satisfied (Yes in S13), the powersource control unit 203 transitions to S14.

In S14, the power source control unit 203 performs processing totransition the power mode to the power save mode, and transitions toS40. This power save mode may be the first power save mode, or may bethe second power save mode.

In S40, the power source control unit 203 determines whether or not thefirst human presence sensor 230 is detecting a person. In a case wherethe first human presence sensor 230 is detecting a person, the flowtransitions to S41, and if not, transitions to S42.

In S41, in a case where the power mode at that time is the first powersave mode, the power source control unit 203 transitions to the secondpower save mode and supplies power to the second human presence sensor231. On the other hand, in a case where the power mode at that time isthe second power save mode, the power source control unit 203 maintainsthe power state and transitions to S15.

In S42, in a case where the power mode at that time is the second powersave mode, the power source control unit 203 transitions to the firstpower save mode and stops power supply to the second human presencesensor 231. On the other hand, in a case where the power mode at thattime is the first power save mode, the power source control unit 203maintains the power state and transitions to S15.

In S15, the power source control unit 203 determines whether or not thehuman presence sensor invalid flag 599 is “0”. In a case wheredetermination is made that the human presence sensor invalid flag 599 is“0” (Yes in S15), the flow transitions to S16, while in a case wheredetermination is made that the human presence sensor invalid flag 599 is“1” (No in S15), the flow transitions to S18.

In S16, the power source control unit 203 determines whether or not ahuman presence sensor (e.g., the first human presence sensor 230) hasentered a non-detecting state. In a case where determination is madethat the human presence sensor is not detecting (Yes in S16), the powersource control unit 203 determines that the user who pressed the powersave key 214 has left the vicinity of the image forming apparatus 100,sets the human presence sensor invalid flag 599 to “1” (S17), andtransitions to S40. On the other hand, In a case where determination ismade that the human presence sensor is detecting a person (No in S16),the power source control unit 203 transitions to S18.

In S18, the power source control unit 203 determines whether or not thenormal power mode transition conditions have been satisfied. In a casewhere the human presence sensor invalid flag 599 is “1” and havingreceived any of the request signals 531, 511, 501, 502, and 503, thepower source control unit 203 determines that the normal power modetransition conditions are satisfied. On the other hand, in a case wherethe human presence sensor invalid flag 599 is “0” and having receivedany of the request signals 511, 501, 502, and 503, the power sourcecontrol unit 203 determines that the normal power mode transitionconditions are satisfied, but if signal 531 is received, determines thatthe normal power mode transition conditions are not satisfied. That isto say, in a case where the human presence sensor invalid flag 599 is“0”, transition to the normal power mode based on detection at thesecond human presence sensor 231 is restricted.

In a case where the power source control unit 203 determines that thenormal power mode transition conditions are not satisfied (No in S18),the power source control unit 203 transitions to S40. On the other hand,in a case where determination is made that the normal power modetransition conditions are satisfied (Yes in S18), the power sourcecontrol unit 203 transitions to the normal power mode (S19).

Also, an arrangement may be made such that, in a case where transitionto the power save mode has been instructed by the power save key 214 andalso the first human presence sensor 230 continues to detect thepresence of a person, power supply to the second human presence sensor231 is stopped, thereby restricting return to the normal power mode dueto detection at the second human presence sensor 231.

Second Embodiment

An overview of difference as to the first embodiment will be describedregarding the second embodiment. The first embodiment has been describedas an arrangement where the image forming apparatus 100 detects that auser who pressed the power save key 214 has left the vicinity, andrestricts unnecessary transition to the normal power mode. In the secondembodiment, if there is no job after having transitions to the normalpower mode, determination is made that the return to normal power modeis due to erroneous detection, and transition to normal power mode isrestricted until the user who has pressed the power save key 214 leavesthe vicinity of the image forming apparatus 100.

Hereinafter, difference as to the first embodiment will be described.Referencing FIG. 7 with regard to power mode transition using sensors,the difference as to FIG. 4 will be described. FIG. 7 is a diagramillustrating an example of a power supply form of the image formingapparatus 100 according to the second embodiment.

In the second embodiment, in a case of a job being performed aftertransitioning to the normal power mode, the CPU 204 transmits a signal533 to the human presence sensor return determining unit 281. The signal533 is used to enable output of the transition request signal 504, basedon human presence detection by the second human presence sensor 231.

FIG. 8 is a diagram illustrating an example of the configuration of thehuman presence sensor return determining unit 281 according to thesecond embodiment. In a case where there is a job after havingtransitioned to the normal power mode, and the power save key 214 hasbeen pressed, the signal 533 is output from the CPU 204 to the invalidflag 600. Upon receiving the signal 533, the invalid flag 600 sets a jobflag stored in an unshown storage unit within the invalid flag 600 to“1”. This job flag is “0” by default. Upon the job flag being “0” andthe invalid flag 600 receiving a signal 530 from the power save key 214,the invalid flag 600 maintains the human presence sensor invalid flag599 to “0” until reception of the signal 532 ceases. On the other hand,if the job flag is “1” and the invalid flag 600 receives the signal 530from the power save key 214, the invalid flag 600 maintains the humanpresence sensor invalid flag 599 to “1”. Other configurations are thesame as those in FIG. 5, so description thereof will be omitted here.

FIG. 9 is a flowchart illustrating an example of power mode transitionoperations in the image forming apparatus according to the secondembodiment. After having transitioned to the normal power mode (S20), ifa job such as copying or scanning is performed (Yes in S21), the CPU 204outputs a signal 533 to the invalid flag 600. Upon receiving the signal533, the invalid flag 600 sets the job flag to “1”. On the other hand,if no job such as copying or scanning is performed (No in S21) afterhaving transitioned to the normal power mode (S20), the CPU 204 does notoutput the signal 533. Without reception of the signal 533, the invalidflag 600 keeps the job flag at “0”.

In a case where the power save key 214 is pressed (Yes in S11), thepower save key 214 outputs the signal 530 to the invalid flag 600. Theinvalid flag 600 receives the signal 530, and in a case of determiningthat the job flag is “0” (Yes in S24), the invalid flag 600 sets thehuman presence sensor invalid flag 599 to “0” (S12).

On the other hand, even if the signal 530 is received, if determiningthat the job flag is “1” (No in S24), the invalid flag 600 keeps thehuman presence sensor invalid flag 599 at “1”. The subsequent operationsare the same as with the case in FIG. 6, so description thereof will beomitted here.

As described above, including whether or not there has been a job afterhaving transitioned to the normal power mode in the determinationcriterion enables power mode transition to be controlled whiledetermining whether or not there has been a transition to the normalpower mode due to an erroneous detection. Thus unnecessary transition tothe normal power mode can be restricted. Accordingly, unnecessary returnfrom the power save mode due to detection by a human presence sensorafter the power save key 214 has been pressed, can be prevented, and asa result, reduction in unnecessary power consumption and extension ofthe life of parts of the apparatus can be realized.

A description has been made here where the human presence sensor returndetermining unit 281 restricts the output of the transition requestsignal 504 and thus restricts return to the normal power mode due todetection by the second human presence sensor 231. However, anarrangement may be made where the human presence sensor returndetermining unit 281 is not provided, and the power source control unit203 directly controls return to the normal power mode due to detectionby the second human presence sensor 231. Only the differences as to thefirst embodiment will be described here as well. In this case, thesignal 533 from the CPU 204 is directly input to the power sourcecontrol unit 203, and the job flag is stored in the power source controlunit 203. In a case where the power save key 214 is pressed anddetermination is made that the job flag is “0”, input of the detectionsignal 531 to the power source control unit 203 is ignored. This will bedescribed below with reference to the flowchart in FIG. 9. In this case,the processes illustrated in FIG. 9 are realized by the power sourcecontrol unit 203 reading out and executing programs stored in an unshownstorage device within the power source control unit 203.

In a case of having received the signal 533 from the CPU 204, the powersource control unit 203 determines that a job such as copying orscanning has been performed (Yes in S21) after having transitioned tothe normal power mode (S20), sets the job flag to “1” (S22), andtransitions to S11. On the other hand, in a case of having received nosignal 533 from the CPU 204, the power source control unit 203determines that no job such as copying or scanning has been performed(No in S21) after having transitioned to the normal power mode (S20). Inthis case, the power source control unit 203 keeps the job flag at “0”(S23), and transitions to S11.

In a case of determining that the power save key 214 has been pressed(Yes in S11), the power source control unit 203 transitions to S24. InS24, the power source control unit 203 determines whether or not the jobflag is “0”. In a case of determining that the job flag is “0” (Yes inS24), the power source control unit 203 sets the human presence sensorinvalid flag 599 to “0”, and transitions to S14. On the other hand, in acase of determining that the job flag is not “0” (No in S24), the powersource control unit 203 keeps the human presence sensor invalid flag 599at “1”, and transitions to S14. The subsequent operations are the sameas with the first embodiment, so description thereof will be omittedhere.

Third Embodiment

An overview of difference as to the first embodiment will be describedregarding the third embodiment. The first embodiment has been describedas an arrangement where two human presence sensors are used to restrictunnecessary transition to the normal power mode in power modetransition. In the third embodiment, a human presence sensor array whereinfrared sensors are arrayed in a matrix form is used as the humanpresence sensor, thereby restricting unnecessary transition to thenormal power mode using a single human presence sensor.

FIGS. 10A and 10B are diagrams illustrating an example of theconfiguration of an image forming apparatus according to the thirdembodiment. FIG. 10A corresponds to a frontal view of the image formingapparatus, and FIG. 10B corresponds to a top view of the image formingapparatus. As illustrated in FIGS. 10A and 10B, the image formingapparatus 100 according to the third embodiment includes a humanpresence sensor array 280.

FIG. 11 is a diagram illustrating an example of a detection range 115 ofthe human presence sensor array 280. The human presence sensor array 280is used as a trigger to transition from the power save mode to thenormal power mode. The human presence sensor array 280 is formed ofinfrared sensors arrayed in matrix form, and can detect objects such ashumans and the like in each of multiple regions into which the sensordetection range is divided. The human presence sensor array 280 can notonly detect that a person has approached and is within the area, butalso can detect that person's movements in detail.

A human presence sensor array determining unit 282 can obtain, from thehuman presence sensor array 280, the position of the region where thehuman presence sensor array 280 has detected a person, as regionposition information. The human presence sensor array 280 is an N×Marray of infrared sensors such as pyroelectric sensors or reflectionsensors (while the present embodiment will be described regarding anexample where an 8×8 array of pyroelectric sensors is formed, thedisclosure is not restricted to this arrangement). The pyroelectricsensors are passive human presence sensors which detect human bodies bydetecting temperature change from infrared rays naturally emitted fromhuman bodies and the like which have heat (heat source). The sensorarray making up the human presence sensor array 280 is not restricted toa pyroelectric sensor array, and may be another type of human presencesensor array. The human presence sensor array 280 may be formed of anysort of sensor array, as long as multiple pyroelectric sensors orreflection sensor or the like are arrayed and human presence can becomprehended in detail. An example where a pyroelectric sensor array isused as the human presence sensor array 280 to detect human motion basedon heat sources will be described.

FIGS. 12A through 12D are diagrams illustrating examples of response ofa human presence sensor array 280. FIG. 12A illustrates the response ofthe human presence sensor array 280 when there are no people nearby. Thehuman presence sensor array 280 has detected no human heat sources, sonone of the sensors are reacting.

FIG. 12B illustrates an example of conditions for a trigger totransition to the normal power mode. In a case where the human presencesensor array 280 has detected that a heat source has occurred in themiddle of the detection area of the human presence sensor array 280,determination is made that a person has approached to use the imageforming apparatus 100, and transition is made to the normal power mode.An arrangement may be made where transition is made to the normal powermode in a case of this response in this area continuing for apredetermined amount of time, to prevent erroneous operation. Also, anarrangement may be made where the sensor information of the humanpresence sensor array 280 is extracted a certain intervals, andtransition is made to the normal power mode in a case where the reactioncontinues a predetermined number of times (twice or more). Here,description will be made regarding transitioning to the normal powermode in a case where there has been the reaction in the rangeillustrated in FIG. 12B. FIGS. 12C and 12D will be described later.

FIGS. 13A and 13B are block diagrams illustrating an example of thehardware configuration of the image forming apparatus 100 according tothe third embodiment. Hereinafter, differences as to the firstembodiment illustrated in FIGS. 3A through 3C will be described.

The first embodiment illustrated in FIG. 3 has two human presencesensors, the first human presence sensor 230 and the second humanpresence sensor 231. Power modes supplying power to the human presencesensors are switched as the first power save mode and the second powersave mode, to avoid unnecessary power usage. On the other hand, thethird embodiment uses the human presence sensor array 280, so there isonly one power save mode. A case where transition is made from the powersave mode to the normal power mode using the human presence sensor array280 is a case where a predetermined condition (FIG. 12B) is satisfied atthe human presence sensor array determining unit 282.

FIG. 13A illustrates blocks to which power is supplied in the normalpower mode, and FIG. 13B illustrates blocks to which power is suppliedin the power save mode. The grayed out portions in FIG. 13B are notsupplied with power in the power save mode.

Hereinafter, differences regarding power mode transition using sensorsas to the first embodiment illustrated in FIG. 4 will be described withreference to FIG. 14. FIG. 14 is a diagram illustrating an example of apower supply form to the image forming apparatus according to the thirdembodiment.

In the third embodiment, the human presence sensor array determiningunit 282 determines whether or not to output a transition request signalto the normal power mode. The human presence sensor array determiningunit 282 determines whether or not conditions such as illustrated inFIG. 12B are satisfied. The human presence sensor array 280 outputs thesignal 531 and signal 534 to the human presence sensor array determiningunit 282. The signal 531 and signal 534 are signals whereby the positionof the region where the human presence sensor array 280 has detected theheat source can be identified, and are used to determine output of thetransition request signal at the human presence sensor array determiningunit 282.

In the example illustrated in FIG. 15, the human presence sensor array280 outputs the signal 531 in a case where a first heat source has beendetected, and outputs the signal 534 in a case where a second heatsource has been detected. However, an arrangement may be made where thehuman presence sensor array 280 outputs only the signal 531 to the humanpresence sensor array determining unit 282 when a heat source isdetected, and the human presence sensor array determining unit 282determines detection of the second heat source from the position ofdetection of the heat source which the signal 531 indicates.

Detailed output restriction of the transition request signal 504 by thehuman presence sensor array determining unit 282 will be described withreference to FIG. 15. FIG. 15 is a diagram illustrating an example ofthe configuration of the human presence sensor array determining unit282 according to the third embodiment.

An arrangement can be made to detect motions of users in detail by usingthe human presence sensor array 280. A case where there are multipleheat source, as in the case in FIG. 12C, can also be determined.

In a case where the human presence sensor array 280 has detected a heatsource 1 which is a first heat source, the human presence sensor array280 outputs the signal 531 to a condition determining circuit 603, andin a case of detecting a heat source 2 which is a second heat source,outputs the signal 534 to the condition determining circuit 603.

The condition determining circuit 603 determines whether or not tooutput the transition request signal based on conditions such asillustrated in FIG. 12B, from the state of the signal 531, and outputs asignal 536 to a logic 601. The condition determining circuit 603 alsodetermines whether or not to output the transition request signal basedon conditions such as illustrated in FIG. 12B, from the state of thesignal 534, and outputs a signal 537 to a logic 602.

While the human presence sensor array 280 is detecting the user whichhas pressed the power save key 214 as illustrated in FIG. 12D, the humanpresence sensor invalid flag 599 is set to “0” by the invalid flag 600,output restriction of the signal 536 is performed, and transition to thenormal power mode is restricted. This enables an operations wheretransition to the normal power mode is restricted regarding the heatsource 1 which is the user who has pressed the power save key 214, whileenabling transition to the normal power mode regarding the heat source 2who is a different user, such as illustrated in FIG. 12C.

In a case where the power save key 214 has been pressed, the signal 530is transmitted from the power save key 214 to the invalid flag 600, andthe transition request signal 536 from the human presence sensor array280 is disabled. In a case where the human presence sensor array 280stops detecting, the human presence sensor array 280 outputs a signal535 to the invalid flag 600, and enables the request signal 536 from thehuman presence sensor array 280. Also, in a case where the heat sourcewhich is the user who has pressed the power save key 214 as beingdetected, and a separate heat source from this heat source is detectedat that time, the signal 534 is output from the human presence sensorarray 280 to the condition determining circuit 603. In a case where thedetection state according to the signal 534 satisfies transitionconditions, the condition determining circuit 603 outputs a requestsignal 537 to the logic 602, and outputs the transition request signal504, for transition to the normal power mode.

FIG. 16 is a flowchart illustrating an example of power mode transitionoperations in the image forming apparatus according to the thirdembodiment. The processing in S11 through S14 is the same as in FIG. 6,so description thereof will be omitted here.

In a case where the human presence sensor invalid flag 599 is “0” (Yesin S15), the invalid flag 600 controls the human presence sensor invalidflag 599 so as to be changed in accordance with the detection signal 535from the human presence sensor array 280.

In a case where the human presence sensor array 280 is in a detectingstate (No in S16), the output of the signal 535 from the human presencesensor array 280 is maintained, and accordingly the invalid flag 600maintains the human presence sensor invalid flag 599 at “0”. In a casewhere the human presence sensor invalid flag 599 is “0”, the humanpresence sensor array determining unit 282 does not transmit thetransition request signal 504 to the power source control unit 203 evenif the detection signal 531 is input from the human presence sensorarray 280 and the predetermined condition (FIG. 12B for example) aresatisfied. Note that determination of conditions such as in FIG. 12B isperformed by the condition determining circuit 603.

Note however, even in a case where the human presence sensor invalidflag 599 is “0”, if the human presence sensor array 280 detects aseparate person (Yes in S30), the human presence sensor arraydetermining unit 282 transmits the transition request signal 504. A caseof detecting another person in S30 is a case where another heat source 2(new object) different from the heat source 1 is detected by the humanpresence sensor array 280 as illustrated in FIG. 12C, thereby satisfyingthe conditions such as in FIG. 12B.

Also, in a case where the human presence sensor array 280 ceasesdetecting (Yes in S16), the output of the signal 535 from the humanpresence sensor array 280 is stopped, and accordingly the invalid flag600 changes the human presence sensor invalid flag 599 to “1” (S17).

In a case where the human presence sensor invalid flag 599 is “1” (No inS15), the invalid flag 600 maintains the human presence sensor invalidflag 599 at “1” regardless of the detection signal 535 from the humanpresence sensor array 280. In a case where the human presence sensorinvalid flag 599 is “1”, the human presence sensor return determiningunit 281 transmits the transition request signal 504 to the power sourcecontrol unit 203 when the detection signal 531 is input from the humanpresence sensor array 280 and predetermined conditions (FIG. 12B forexample) are satisfied. Determination of conditions such as in FIG. 12Bis performed by the condition determining circuit 603.

In the third embodiment, in a case where the human presence sensorinvalid flag 599 is “0”, the human presence sensor array determiningunit 282 does not output the transition request signal 504 when only oneheat source is detected by the human presence sensor array 280.Accordingly, the normal power mode transition conditions are notsatisfied in a case where the human presence sensor array 280 hasdetected the person who has pressed the power save key 214. However,even if the human presence sensor invalid flag 599 is “0”, the humanpresence sensor array determining unit 282 outputs the transitionrequest signal 504 if two or more heat sources are detected by the humanpresence sensor array 280. Accordingly, in a case where the humanpresence sensor array 280 has detected a separate person from the personwho pressed the power save key 214 under conditions such as in FIG. 12B,the normal power mode transition conditions are satisfied. Of course,output of the transition request signal 504, is not restricted when thehuman presence sensor invalid flag 599 is “1”, is in a case where thehuman presence sensor array 280 detects a person under conditions as inFIG. 12B, normal power mode transition conditions are satisfied.

Using the human presence sensor array 280 as described above enablestransitioning to the normal power mode to be restricted regarding theuser who has pressed the power save key 214, while enablingtransitioning to the normal power mode for other users. Accordingly,unnecessary recovery from the power save mode due to detection of humanpresence sensors after the power save key 214 has been pressed can beprevented, thereby improving user usability. Thus, the same advantage asusing two human presence sensors can be obtained by using the humanpresence sensor array 280. The third embodiment does away with the needto switch between the first power save mode and the second power savemode.

Description has been made above regarding an arrangement where the humanpresence sensor array determining unit 282 restricts the output of thetransition request signal 504, and restricts return to the normal powermode due to detection by the human presence sensor array 280. However,an arrangement may be made where no human presence sensor arraydetermining unit 282 is provided, and the power source control unit 203directly restricts return to the normal power mode by detection of thehuman presence sensor array 280. In this case as well, only thedifferences as to the first embodiment will be described. In this case,the signals 531 and 534 from the human presence sensor array 280 aredirectly input to the power source control unit 203, and the humanpresence sensor invalid flag 599 is stored within the power sourcecontrol unit 203. In a case where the power save key 214 is pressed andthe human presence sensor invalid flag 599 is determined to be “0”, thepower source control unit 203 ignores input of the detection signal 531thereto. On the other hand, if the detection signal 534 is input to thepower source control unit 203, the power source control unit 203 doesnot ignore even if the human presence sensor invalid flag 599 is “0”,and returns to the normal power mode in a case where conditions such asin FIG. 12B are satisfied.

Description will be made below with reference to the flowchart in FIG.16. In this case, the processes illustrated in FIG. 16 are realized bythe power source control unit 203 reading out and executing programsstored in an unshown storage device within the power source control unit203.

In S15, the power source control unit 203 determines whether or not thehuman presence sensor invalid flag 599 is “0”. In a case of determiningthat the human presence sensor invalid flag 599 is “0” (Yes in S15), theflow transitions to S16, while in a case of determining that the humanpresence sensor invalid flag 599 is “1” (No in S15), the flowtransitions to S18.

In S16, the power source control unit 203 determines whether or not thehuman presence sensor array 280 has ceased detecting. In a case wheredetermination is made that the human presence sensor array 280 hasceased detecting (Yes in S16), the power source control unit 203determines that the user who pressed the power save key 214 has left thevicinity of the image forming apparatus 100 sets the human presencesensor invalid flag 599 to “1” (S17), and transitions to S15. In a caseof determining in S16 that the human presence sensor array is detectinga person (No in S16), the power source control unit 203 transitions toS30.

In S30, the power source control unit 203 determines whether or not thehuman presence sensor array 280 has detected another person (newobject). A case where a different person has been detected in S30corresponds to a case where the human presence sensor array 280 hasdetected a heat source 2 which is different from the heat source 1 asillustrated in FIG. 12C, so that conditions such as in FIG. 12B aresatisfied.

In a case where determination is made in S30 that the human presencesensor array 280 has not detected another person (new object) (No inS16), the power source control unit 203 transitions to S15. On the otherhand, in a case where determination is made in S30 that the humanpresence sensor array 280 has detected another person (new object) (Yesin S30), the power source control unit 203 transitions to S18.

In S18, the power source control unit 203 determines whether or notnormal power mode transition conditions have been satisfied. In a casewhere the human presence sensor invalid flag 599 is “1” and havingreceived any of the request signals 531, 511, 501, 502, and 503, thepower source control unit 203 determines that the normal power modetransition conditions are satisfied. On the other hand, in a case wherethe human presence sensor invalid flag 599 is “0” and having receivedany of the request signals 511, 501, 502, and 503, the power sourcecontrol unit 203 determines that the normal power mode transitionconditions are satisfied, but if signal 531 is received, determines thatthe normal power mode transition conditions are not satisfied. Furtherin this case, upon having received the signal 534, the power sourcecontrol unit 203 determines that normal power mode transition conditionshave been satisfied. That is to say, in a case where the human presencesensor invalid flag 599 is “1”, detection by the human presence sensorarray 280 of the user which has pressed by power save key 214 isignored, but detection of another use is enabled, and control iseffected so as to transition to the normal power mode.

Note that while a human presence sensor array is used in the presentembodiment, any sort of human presence sensor may be used as long as itis a human presence sensor which can recognize the number of objectsbeing detected. That is to say, a human presence sensor which canrecognized a user separate to the user which has pressed the power savekey 214 is sufficient.

Also, a configuration where the second embodiment and the thirdembodiment are combined may be made. That is to say, in a case wherethere is no job after transitioning to the normal power mode, the jobflag is set to “0”, and if there is a job, the job flag is set to “1”. Aconfiguration which sets the human presence sensor invalid flag 599 to“0” of the job flag is “0” in a case where the power save key 214 ispressed, is added to the third embodiment. Accordingly, in addition tothe configuration of the third embodiment, a configuration can be addedwhich restricts transition to the normal power mode in a case whereinstruction to the power save mode has been given by the power save key214 without a job being input after transitioning to the normal powermode.

Also, the configurations and contents of various data described aboveare not restricted thusly, and it is needless to say that variousconfigurations and contents thereof may be made according to usage andpurpose.

Also, while embodiments of the disclosure have been illustrated, thedisclosed embodiments may assume various modes as a system, apparatus,method, program, storage medium, or the like, for example. Specifically,the disclosed embodiments may be applied to a system configuredincluding multiple devices, or may be applied to an apparatus includinga single device. All combinations of the above-described embodiments arealso encompassed by the disclosure.

Other Embodiments

The disclosure can also be carried out by software (programs) realizingthe functions of the above-described embodiments being supplied to asystem or apparatus via network or any of various types of storagemedia, and a computer (or CPU or MPU or the like) of the system orapparatus reading out and executing the program. The disclosure may beapplied to a system configured including multiple devices, or may beapplied to an apparatus including a single device.

The disclosure is not restricted to the above-described embodiments;rather, various modifications (including organic combinations of theembodiments) may be made based on the essence of the disclosure, withoutdeparting from the scope of the disclosure. Further, all combinations ofthe embodiments described above and modifications thereof areencompassed by the disclosure.

Other Embodiments

Embodiments of the disclosure can also be realized by a computer of asystem or apparatus that reads out and executes computer executableinstructions recorded on a storage medium (e.g., non-transitorycomputer-readable storage medium) to perform the functions of one ormore of the above-described embodiment(s), and by a method performed bythe computer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s). The computer may comprise one or more of a centralprocessing unit (CPU), micro processing unit (MPU), or other circuitry,and may include a network of separate computers or separate computerprocessors. The computer executable instructions may be provided to thecomputer, for example, from a network or the storage medium. The storagemedium may include, for example, one or more of a hard disk, arandom-access memory (RAM), a read only memory (ROM), a storage ofdistributed computing systems, an optical disk (such as a compact disc(CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flashmemory device, a memory card, and the like.

While the disclosure has been described with reference to exemplaryembodiments, it is to be understood that the disclosure is not limitedto the disclosed exemplary embodiments. The scope of the followingclaims is to be accorded the broadest interpretation so as to encompassall such modifications and equivalent structures and functions.

1. An image forming apparatus, having a power state including at least astandby state, and a power save state in which less power is consumedthan in the standby state, the image forming apparatus comprising: areception unit configured to receive user operations to shift the powerstate from the standby state to the power save state; a detecting unitconfigured to detect a user; and a power control unit configured toshift the power state from the power save state to the standby state inaccordance with detection of a user by the detecting unit, and to shiftthe power state from the standby state to the power save state inaccordance with the user operation received at the reception unit;wherein, even if the detecting unit detects a user, the power controlunit does not shift the power state from the power save state to thestandby state during a period, after the power control unit has shiftedthe power state from the power save state to the standby state inaccordance with the detection of a user by the detecting unit, in whicha user is present around the image forming apparatus.
 2. The imageforming apparatus according to claim 1, wherein the detecting unitdetects a user being present around the image forming apparatus.
 3. Theimage forming apparatus according to claim 1, further comprising anotherdetecting unit configured to detect a user being present around theimage forming apparatus.
 4. The image forming apparatus according toclaim 2, wherein the detecting unit is a sensor array where sensorsreceiving infrared light are arrayed in a matrix form.
 5. The imageforming apparatus according to claim 1, further comprising anotherdetecting unit having a larger detecting range than a detecting range ofthe detecting unit.
 6. The image forming apparatus according to claim 5,wherein, in a case of the another detecting unit detecting a user, thedetecting unit is enabled to detect a user; and wherein the powercontrol unit shifts the power state from the power save state to thestandby state in accordance with the detection of a user by thedetecting unit.
 7. The image forming apparatus according to claim 1,further comprising a storage unit configured to store information in acase where the reception unit receives the user operation, theinformation being deleted in a case where a user being present aroundthe image forming apparatus does not exist; wherein, if the storage unitstores the information, the power control unit does not shift the powerstate from the power save state to the standby state even if thedetecting unit detects a user.
 8. The image forming apparatus accordingto claim 1, further comprising a printing unit configured to print animage on a sheet based on image data.
 9. A control method of an imageforming apparatus, having a power state including at least a standbystate, and a power save state in which less power is consumed than inthe standby state, the method comprising: receiving user operation toshift the power state from the standby state to the power save state bya reception unit; detecting a user by a detecting unit; and shifting thepower state from the power save state to the standby state in accordancewith detection of a user by the detecting unit; shifting the power statefrom the standby state to the power save state in accordance with theuser operation received by the reception unit; and prohibiting, even ifthe detecting unit detects a user, the power state from shifting fromthe power save state to the standby state during a period, after thepower state has shifted from the power save state to the standby statein accordance with the detection of a user by the detecting unit, inwhich a user is present around the image forming apparatus.
 10. Anon-transitory recording medium storing a program causing a computer ofan image forming apparatus, having a power state including at least astandby state, and a power save state in which less power is consumedthan in the standby state, to perform operations, the operationscomprising: receiving user operation to shift the power state from thestandby state to the power save state by a reception unit; detecting auser by a detecting unit; shifting the power state from the power savestate to the standby state in accordance with detection of a user by thedetecting unit shifting the power state from the standby state to thepower save state in accordance with the user operation received by thereception unit; and prohibiting, even if the detecting unit detects auser, the power state from shifting from the power save state to thestandby state during a period, after the power state has shifted fromthe power save state to the standby state in accordance with thedetection of a user by the detecting unit, in which a user is presentaround the image forming apparatus.